1. Field of the Invention
The present invention relates to an improvement in friction plates used, for example in a multiple-plate friction engagement apparatus, such as a lock-up clutch in an automatic transmission of a motor vehicle or in a transmission of a motor bike.
2. Related Background Art
In the past, a friction plate has been manufactured by adhering a plurality of friction material segments to an annular core plate in an annular fashion. For example, as shown in FIGS. 3 and 4, the segments have been interconnected by connecting portions configured similar to pieces of jigsaw puzzles.
However, when the friction material segments are stamped from a friction material tape, burrs can be generated at ends of the stamped friction material segments.
FIG. 6 is a sectional view showing conventional connecting portions in detail. Friction material segments 12 are adhered to the surface of a core plate 11 in such a manner that burrs formed on connecting portions 16 of the stamped friction material segments 12 are protruded from a frictional engagement surface, i.e., toward an associated member 17.
In the above-mentioned conventional friction plate, if the friction material segments are adhered to the core plate in such a manner that the burrs are protruded toward the associated member, the friction material is locally contacted with the associated member via the burrs, with the result that the connecting portions of the friction material segments may be peeled or ripped off.